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-rw-r--r--arch/csky/lib/delay.c39
1 files changed, 39 insertions, 0 deletions
diff --git a/arch/csky/lib/delay.c b/arch/csky/lib/delay.c
new file mode 100644
index 0000000000..f5db317313
--- /dev/null
+++ b/arch/csky/lib/delay.c
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: GPL-2.0
+// Copyright (C) 2018 Hangzhou C-SKY Microsystems co.,ltd.
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/init.h>
+#include <linux/delay.h>
+
+void __aligned(8) __delay(unsigned long loops)
+{
+ asm volatile (
+ "mov r0, r0\n"
+ "1:declt %0\n"
+ "bf 1b"
+ : "=r"(loops)
+ : "0"(loops));
+}
+EXPORT_SYMBOL(__delay);
+
+void __const_udelay(unsigned long xloops)
+{
+ unsigned long long loops;
+
+ loops = (unsigned long long)xloops * loops_per_jiffy * HZ;
+
+ __delay(loops >> 32);
+}
+EXPORT_SYMBOL(__const_udelay);
+
+void __udelay(unsigned long usecs)
+{
+ __const_udelay(usecs * 0x10C7UL); /* 2**32 / 1000000 (rounded up) */
+}
+EXPORT_SYMBOL(__udelay);
+
+void __ndelay(unsigned long nsecs)
+{
+ __const_udelay(nsecs * 0x5UL); /* 2**32 / 1000000000 (rounded up) */
+}
+EXPORT_SYMBOL(__ndelay);